They're usually elusive, shy and unsociable – but a Breckland heath has offered a glimpse of a 'secret gathering' of stone-curlews as they prepare for their annual migration.
Cavenham Heath, near Mildenhall, has become a departure lounge for these rarely-seen travellers, as they congregate to roost and feed before flying more than 1,000 miles in search of some winter warmth in northern Africa and southern Spain.
The stone-curlew is one of the UK's rarest breeding birds. They are notoriously secretive in the breeding season and, as many nest on private or inaccessible land, there are few public places for people to go and see these unusual birds without the risk of disturbing them.
Consequently, the birds and their breeding grounds are closely guarded by the conservationists and farmers who have been working for decades to help revive the fortunes of the species after the population reached a historic low in the 1980s.
So the RSPB and Natural England, which manages the reserve at Cavenham Heath, have invited bird-watchers to join them for guided walks to enjoy this nature spectacle.
Tim Cowan, RSPB Brecks project manager, said: 'When they have got nests they are very difficult to see so this is a good opportunity to see them when they are a bit more confiding.
'Most of the other roosts are on private land, or you cannot reach them. But here you can see them from a public track on the nature reserve.
'The record here in 2011 was 157 birds. Up until a couple of years ago we were regularly getting 90-100 in the autumn, but the last couple of years there has not been so many here, but there are other roost sites in the Brecks that have larger numbers.
'There are probably about 20 out this year. We have received a report of 40-plus, but we have not seen those numbers ourselves.
'The reason they are in the Brecks at all is because stone-curlews are associated with poor soils. They like bare, stony ground or sparsely-vegetated ground when they are nesting.
'Here the rabbit numbers have crashed in recent years, as they have on many Brecks heaths. And it has not been as heavily grazed, which might be why we see fewer birds roosting. In previous years the grass was much shorter and there were more rabbits.'
Mr Cowan said partnership projects with landowners and farmers to protect stone-curlews and their nesting sites had helped the resurgence of the species, after its UK numbers dropped to an estimated 150 breeding pairs in the mid 1980s. Now the population has increased to around 400 pairs – with almost two thirds of them in the Brecks.
Mike Taylor, Cavenham Heath reserve manager for Natural England, said: 'A big part of Natural England's work is public engagement, and trying to enthuse the public about nature conservation having somewhere like this where you can be right in the middle of a fantastic habitat is really valuable.
'People like Tim have been working for many years with farmers, and with us, to ensure that the stone curlew recovery has continued. I have been here for 18 years and you never lose the thrill of seeing them.'
HOW TO SPOT A STONE-CURLEW
The stone-curlew is a crow-sized bird with a large head, long yellow legs and relatively long wings and tail.
Active at night, its large yellow eyes enable it to locate food when it is dark.
It is not related to curlews and gets its name from its curlew-like call.
Every autumn, at the end of the breeding season when the chicks have left their nests, dozens of these usually unsociable birds gather at Breckland heathland sites, where they roost and feed before migrating south for the winter, usually leaving in October.
The RSPB and Natural England are leading free guided walks to see the stone-curlew roost at Cavenham Heath, Tuddenham, IP28 6TB.
The final event is on September 12, from 6pm until dark. Booking is essential, either online or by contacting 01728 648281 or tim.cowan@rspb.org.uk.
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